A knee joint prosthesis typically comprises a femoral component and a tibial component. The femoral component and tibial component are designed to be surgically attached to the distal end of the femur and the proximal end of the tibia respectively. The femoral component is further designed to cooperate with the tibial component in simulating the articulating motion of an anatomical knee joint. Knee joint prostheses, in combination with ligaments and muscles, attempt to duplicate natural knee motion as well as absorb and control forces generated during the range of flexion.
While known knee joint prostheses have proven to be effective in replacing the anatomical knee joint, they nevertheless have several disadvantages. For example, knee joint prostheses sometimes lack adaptability to implant conveniently with a given patient. In this regard, in a normally shaped femur, the central canal is typically offset from the center of the femoral articulating surfaces. Furthermore, the central femoral canal may present various valgus angles from one patient to another.
While knee joint prosthesis having offset femoral stems or femoral stems providing a range of valgus angles are known, they nevertheless can be subject to certain improvement.